Question: Complete the recursive formula of the arithmetic sequence $12, 10, 8, 6,...$. $b(1)=$
Explanation: The first term is $12$ and the common difference is $-2$. ${-2\,\curvearrowright}$ ${-2\,\curvearrowright}$ ${-2\,\curvearrowright}$ $12,$ $10,$ $8,$ $6,...$ This is the recursive formula of $12, 10, 8, 6,...$ $\begin{cases} b(1)=12 \\\\ b(n)=b(n-1)+(-2) \end{cases}$